I'm not much positive about Barcelona's chance to eliminate Napoli honestly. Because their game is just not good enough. I believe that they haven't faced a real challenge yet. Porto were the second strongest team in the group but Barcelona won against them twice anyway. But I think Napoli are a bigger challenge than Porto for them.
Napoli have a stronger squad in the first place. They have a very dangerous player like Osimhen in their offense line. They are just trying to improve their form lately. But until this matchup I think Napoli will be in a better shape than now. If Barcelona don't make improvement at the same time then they can really say goodbye to the CL early.
But I think Barcelona was lucky during this season of the Champions League because we know they are not in their best form and this Barcelona we currently see can definitely lose games easily against other teams. While Barcelona is also not in the form to face with stronger teams, however Napoli has players like Osimhen as you just said and since Barcelona's defenders are weak this can be dangerous.
Barcelona will never go to their prime again. Time flies and everything is changing right now. The financial trouble has prevented barcelona to build the good clubs. It will always be like that. The only solution to sell barcelona to the big investors. Barcelona shall consider it as the only option owned by the club right now. Im not willing to argue that but in fact, barcelona is still in the very big crisis right now. Xavi is going to face another problem caused by he will have very limited budget to build the team. There will be some players to leave from barcelona.
Laporta is also having the same problem as he has no club what shall be doing to save the club. Xasvi needs to think even more than before. There will be revamp to happen in barcelona soon and he needs to prepare everything to make sure barcelona will not be losing its position.
Barcelona must let some players go out due to the financial pressure for the club. The club can't sign new players if there will be no a lot of players to go out.